Three years after Nathan Dunlap coldly murdered four people at a Chuck E. Cheese in Aurora, his attorneys faced a strategic legal decision.

Should they mount a defense of mental illness given the certainty the jury would thereby learn he’d staged at least one incident of mania at the state mental hospital and engaged in menacing behavior there as well?

Or should they try to sway the jury into sparing his life by recounting his atrociously brutal childhood and suggesting it helped explain Dunlap’s brutality?

They chose the latter course, and eventually failed. Dunlap received the death penalty for his crime spree in 1993, which he and a subsequent set of attorneys are still trying to overturn. They say Dunlap is mentally ill and that his original attorneys, in refusing to adopt such a defense, failed to provide Dunlap with effective counsel.

Not only is this a dubious claim, similar arguments have been rejected before — for example, by Arapahoe District Judge John Leopold in 2004. Dunlap’s first attorneys were seasoned professionals whose strategy was defensible, and remains so in hindsight. Dunlap’s problem wasn’t an incompetent defense. It was the shocking evidence of wanton cruelty.

We say this not because we wish to see Dunlap executed. To the contrary, we oppose the death penalty on moral and practical grounds and hope lawmakers — or voters, through a ballot measure — someday allow Colorado to join the ranks of more than a dozen states where capital punishment has been outlawed. But so long as a death statute is on the books, it should be enforced as it was intended, not turned into a sham through seemingly endless longshot appeals that run for decades.

Colorado is not one of those states with a questionable record in sentencing murderers to death. Only the very worst predators who’ve killed multiple people or tortured their victim and whose guilt is not remotely in doubt are ever sentenced to die.

Since 1967, Colorado has executed just one person — and true to form, Gary Davis was a murderer/torturer. Meanwhile, several others condemned to die have been spared through natural death or because they had their sentences changed to life by a higher court — although not, we emphasize, because there was the slightest question about guilt.

We consider the rare incidence of executions in Colorado an argument in itself to abolish the sentence. A single execution in 45 years is obviously no deterrent. And the deterrent argument would not gain much strength even if everyone sentenced to die had been executed, given the small number involved and the lengthy delays — sometimes for decades — that precede executions.

Colorado prosecutors and juries clearly aren’t interested in the wholesale application of the death sentence — not even to brutal cold-blooded killers. Yet every now and then, after careful deliberation, prosecutors and juries do make an exception. And no one should be surprised that Dunlap was one of them.